FLT CREW OF B747-400 EXPERIENCE BODY GEAR TIRE FAILURE PRIOR TO V1 ON TKOF. OPT TO CONTINUE TKOF DUE TO HIGH SPD ABORT CONSIDERATIONS. FLY TO DEST AND LAND SAFELY UNDER EMER CONDITIONS.

Narrative

I WAS THE CAPT. DISPATCH COMMENTS INCLUDED A 'BRAKE TORQUE LIMITER CTL' INOP ON THE L BODY GEAR; AFT INBOARD WHEEL. WE WERE PLANNED WITH NO SEVERE WX ENRTE. THE 'FINAL WTS' GAVE US A TKOF GROSS OF 873.9 LBS WHICH ALLOWED AN ASSUMED TEMP OF 33 DEGS C AND A SMALL REDUCTION IN TKOF EPR TO 1.51 AT FLAPS 10 DEGS. IT WAS A LONG TAXI ON A HOT DAY WHICH I ASSUME WAS A CONTRIBUTING FACTOR TO OUR EVENTUAL PROB. ALL CHKLISTS WERE ACCOMPLISHED IN ORDER. AT APPROX 120 KTS ON THE TKOF ROLL; WE FELT A NOTICEABLY STRONG VIBRATION IN THE YOKE -- SIMILAR TO A NOSEWHEEL SHIMMY. OUR TKOF SPDS WERE: V1 149 KTS; VR 165 KTS; AND V2 178 KTS. WITH NO OTHER COCKPIT INDICATIONS TO ACCOMPANY THE VIBRATION; I ALLOWED THE TKOF TO CONTINUE RATHER THAN RISK A HIGH SPD ABORT; HVY WT; ON A HOT DAY. WHEN THE PF ANNOUNCED 'POSITIVE CLB; GEAR UP' I GAVE A QUICK CONSIDERATION TO LEAVING THE GEAR DOWN; HOWEVER; OUR DEP WAS OVER THE CITY AND DEBRIS FROM THE TIRE COULD HAVE BEEN AN ISSUE. I ALSO CONSIDERED THE PERFORMANCE CONSEQUENCES OF A RESULTANT ENG FAILURE. I RAISED THE GEAR AND QUICKLY LOOKED AT THE EICAS SYNOPTIC FOR GEAR. THE DOORS HAD CLOSED PROPERLY; AND BRAKE TEMPS ALL SHOWED ZERO. THE HYD SYNOPTIC SHOWED QUANTITIES STEADY. ONCE WE RECEIVED THE TURN EASTWARD; WE BEGAN TO ANALYZE OUR SIT. THE FO CONTINUED TO FLY THE ACFT; I COMMUNICATED WITH ATC; AND THE RELIEF PLT CALLED BACK TO THE TWR TO ASK IF THEY HAD NOTICED ANY PROBS WITH OUR TKOF. TWR CONFIRMED A POSSIBLE BLOWN TIRE WITH RUBBER ON THE RWY. TWR ADVISED US THAT THEY WERE CLOSING THE RWY FOR THE CLEANUP. THE FLT ATTENDANTS CALLED ME TO RPT 2-3 'POPS' DURING TKOF; WITH NOISE AND VIBRATION ON BOTH SIDES OF THE ACFT. AT THIS POINT IT WAS OBVIOUS THAT WE HAD LOST AT LEAST 1 TIRE; AND; AT OVER 860.0 LBS GROSS WT; WE WERE FACED WITH DUMPING 230.0 LBS OF FUEL AND RETURNING; OR CONTINUING ON TO DEST; OR POSSIBLY DIVERTING. WE CHKED BOTH THE HANDBOOK AND THE COMPANY OPS MANUAL FOR ANY PROCS THAT MIGHT APPLY TO OUR SIT -- WE FOUND NONE. I CONTACTED DISPATCH VIA SATCOM TO DISCUSS OUR OPTIONS. ALL HYDS; ELECTRICS; AND FLT CTLS WERE NORMAL; AS WAS PRESSURIZATION. THE ACFT WAS HANDLING PROPERLY WITH NO VIBRATIONS; SO; IT WAS AGREED THAT WE SHOULD CONTINUE TO DEST AS PLANNED. I DISCUSSED WITH DISPATCH THE RWY PREFERENCE FOR DEST; EVEN THOUGH THE FORECAST WAS FOR A POSSIBLE SWITCH TO ANOTHER RWY. WE AGREED THAT IT WAS NOT NECESSARY TO DECLARE AN 'EMER;' AND THAT A NORMAL LNDG WAS ANTICIPATED. ALTHOUGH AN 'EMER' WAS NOT DECLARED; I THOUGHT IT PRUDENT TO HAVE AT LEAST 1 FIRE TRUCK AVAILABLE TO ASSIST US AS NEEDED. I CALLED THE PURSER TO THE COCKPIT AND AFTER SHE INFORMED THE CABIN CREW; I MADE A PA ANNOUNCEMENT TO THE PAX EXPLAINING THE PROB; THE STATUS OF THE ACFT; AND THE PLAN. THE FLT PROGRESSED SMOOTHLY ACROSS THE OCEAN. ABOUT 1 HR PRIOR TO TOUCHDOWN; I AGAIN CONTACTED DISPATCH TO SEE IF OPS HAD ANY ADDITIONAL INFO THAT MIGHT HELP US DETERMINE HOW MANY TIRES WERE INVOLVED. TO OUR SURPRISE; THE NEW GUESS WAS THAT WE MAY HAVE LOST UP TO 3 TIRES; AND THAT THE DEBRIS FIELD WE LEFT BEHIND EXTENDED 1500 METERS! THAT PROMPTED MY CONCERN ON LNDG CONTROLLABILITY. ATC THEN UNILATERALLY DECLARED US AN 'EMER' ACFT AND PLANNED TO DEPLOY THE WHOLE ARMADA OF EMER EQUIP ASSOCIATED WITH THAT STATUS. WE BRIEFED A FLAPS 30 DEG APCH USING NO AUTOBRAKES. ARR ATIS REFLECTED A 500 FT CEILING WITH DRIZZLE AND WIND 100 DEGS AT 5 KTS; A SLIGHT TAILWIND. WE AGAIN CHKED LNDG PERFORMANCE WITH UP TO 10 KTS TAILWIND AND HAD MORE THAN ENOUGH MARGIN. ONCE AGAIN I CALLED THE PURSER TO THE COCKPIT TO FINALIZE APCH PLANS WITH THE CABIN CREW. SHE REVIEWED OUR BRIEFING WITH HER CREW. WE BRIEFED THE EVAC PROC SHOULD IT BECOME NECESSARY. I THEN MADE A PA ANNOUNCEMENT TO REASSURE THE PAX OF OUR ARR PLANS. I ELECTED TO FLY THE APCH AND LNDG; AND AN UNEVENTFUL ROLLOUT WITH MINIMAL VIBRATION WAS NOTED. WE CLRED THE RWY AT TXWY AS PLANNED. MAINT CONNECTED A HEADSET TO THE ACFT AND INFORMED US THAT THE R BODY GEAR; AFT INBOARD TIRE HAD BLOWN; AND THAT WE WOULDBE TOWED TO THE GATE. THERE WAS ONLY 1 TIRE BLOWN; BUT THE DEBRIS HAD PUNCHED 2 SMALL HOLES IN THE FUSELAGE AND THERE WAS A DENT IN THE GEAR DOOR. WE CONDUCTED THE 'TOW IN' ADDITIONAL PROC; AND WERE TOWED TO AN UNEVENTFUL PARKING AT THE GATE.